BEHAVIORAL MONITORING OF TRAINED INSECTS FOR CHEMICAL DETECTION

Authors: RAINS, GLEN - UNIVERSITY OF GEORGIA; UTLEY, SAMUEL - UNIVERSITY OF GEORGIA; Lewis, Wallace

Submitted to: Biotechnology Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/24/2005
Publication Date: 2/1/2006
Citation: Rains, G.C., Utley, S.L., Lewis, W.J. 2006. Behavioral monitoring of trained insects for chemical detection. Biotechnology Progress. 22:2-8.

Interpretive Summary: Parasitic wasps optimize their ability to locate food and host insect resources by learning and subsequently using associated chemical and visual cues. ARS scientists at Tifton and the University of Georgia together with other cooperators, are exploring whether the remarkable olfactory and learning abilities of these organisms can be harnessed for agricultural and military intelligence and detection purposes, such as monitoring for food safety concerns. The parasitic wasp, Microplitis croceipes (Cresson) (Hymenoptera: Braconidae), can be trained to respond to target odors by allowing them to encounter the odors in association with food or hosts. One such response to a target odor is known as “area restricted searching,” whereby, trained wasps exhibit crowding within the same area where the target odor is detected. A portable handheld, computer vision device dubbed, Wasp Hound, was developed for using the wasps as detectors. Trained wasps, containerized in the device, provided distinct measurable responses to air samples containing low concentrations of the test chemical, 3-octanone, a common fungal volatile chemical. The development and initial demonstration of this methodology greatly advances the feasibility of this important detection and monitoring technology and accelerates it prospects for transfer into practical application.

Technical Abstract: A portable, handheld volatile odor detector (Wasp Hound) that utilizes a computer vision system and Microplitis croceipes (Cresson) (Hymenoptera: Braconidae), a parasitoid wasp, as the chemical sensor was created. Five wasps were placed in a test cartridge and placed inside the device. Wasps were either untrailed, or trained by associative learning to detect 3-octanone, a common fungal volatile chemical. The Wasp Hound sampled air from the head space of corn samples prepared within the lad, and coupled with Visual Cortex a software program developed using the LabView graphical programming language, monitored and analyzed wasp behavior. The Wasp Hound, with conditioned wasps, was able to detect 0.5 mg of 3-octanone within a 240 ml glass container filled with feed coA portable, handheld volatile odor detector (Wasp Hound) that utilizes a computer vision system and Microplitis croceipes (Cresson) (Hymenoptera: Braconidae), a parasitoid wasp, as the chemical sensor was created. Five wasps were placed in a test cartridge and placed inside the device. Wasps were either untrained, or trained by associative learning to detect 3-octanone, a common fungal volatile chemical. The Wasp Hound sampled air from the head space of corn samples prepared within the lab and, coupled with Visual Cortex a software program developed using the LabView graphical programming language, monitored and analyzed wasp behavior. The Wasp Hound, with conditioned wasps, was able to detect 0.5 mg of 3-octanone within a 240 ml glass container filled with feed corn (is approximately equal to 2.6x10-5mol/L). The Wasp Hound response to the control (corn alone) and a different chemical placed in the corn (0.5 mg of myrcene) was significantly different than the response to the 3-octanone. Wasp Hound results from untrained wasps were significantly different from trained wasps when comparing the responses to 3-octanone. The Wasp Hound may provide a unique method for monitoring grains, peanuts, and tree nuts for fungal growth associated with toxin production.